It was Tony's mention of listening to Travels with My Aunt (made into a movie with Maggie Smith) that encouraged me to listen to Our Man in Havana. I had seen the movie with Alec Guinness years ago, but remember only his white suit and being confused. Of course I know and love some of his other works through movies, The End of the Affair and the wonderful The Third Man.
The protagonist is a poor schlub named Wormold who sells vacuum cleaners in Havana. His wife had left years before and he is unable to say no to his teenage daughter Milly. For no clear reason he is approached by a British agent named Hawthorne to be a spy for the British; Milly's desire for a horse and other expenses makes him willing to give this a try. He creates fake agents and sends in their fictitious reports, including some diagrams purporting to be weaponry that are actually vacuum cleaner nozzle diagrams. Occasionally we hear from the higher authorities in London who are pleased with Wormold's reports and for their own bureaucratic infighting reasons find it inconvenient to check with others to determine authenticity.
As some begin to doubt Wormold's reports, a man with the same name as one of his "agents" dies in an accident and his credibility rises. He is very confused by this turn of events, but by this time he has been sent an assistant (Beatrice) and someone to send and receive messages. A big moment comes when he is warned that he is to be poisoned at the annual businessman's luncheon. Against his friends' advice, he attends anyway and manages to avoid being poisoned, though a dog dies who lapped up whiskey meant for him.
Once you are accustomed to the disdain for, well, for just about everybody, it's a fun and clever book. He was an amazing writer.
Graham Greene, Our Man in Havana, Viking Press, 1958, 247 pages (I listened to the audiobook). Available at the UVa and public libraries and from Amazon.